One of the most common methods of accurately controlling an air-fuel ratio of an internal combustion engine is means for measuring an intake air flow rate and an intake air temperature to sequentially calculate a fuel injection amount at which a combustion status is optimal. A thermal flow measuring device is equipped with a flow rate detection unit including a heating resistor, a temperature detection unit including a thermistor, and an electronic control circuit unit that controls the heating temperature of the flow rate detection unit. A known conventional flow measuring device has a thermistor element for temperature measurement disposed in an intake pipe of an internal combustion engine to allow it to be hardly affected by heat from the internal combustion engine in order to thereby achieve a cooling effect by intake air.
A structure with such a technique applied to includes a flow measuring device described in Patent Document 1.